Question

this question refers to the food web diagram. what actions may occur if parrotfish were greatly overfished in this ecosystem? select all that apply. there would be too many zooplankton. sharks would have fewer parrotfish to feed on. unicornfish would be greatly affected by a reduction of parrotfish. fewer corals would be consumed. there would be fewer phytoplankton. nothing would be affected if the parrotfish population was reduced.

Explanation:

• Sharks would have fewer parrotfish to feed on: As shown in the food - web, sharks prey on parrotfish. Overfishing parrotfish directly reduces their availability as food for sharks.
• Fewer corals would be consumed: Parrotfish eat corals (as per the food - web). With fewer parrotfish, there is less consumption of corals.
• There would be too many zooplankton: Parrotfish do not directly consume zooplankton. But if parrotfish are overfished, and assuming no other major changes in the short - term (except for the direct relationships shown), the main consumers of corals (parrotfish) are reduced. However, if we consider the flow, corals are not being consumed as much. But looking at the food - web, parrotfish have no direct predation on zooplankton. But if we assume that the main change is in the parrotfish - related part. Wait, actually, parrotfish eat corals. If parrotfish are overfished, corals may increase (but this is not one of the options). Another approach: Sharks eat parrotfish. If parrotfish are overfished, sharks have less food (so that option is valid). Parrotfish eat corals, so fewer parrotfish means fewer corals are eaten (valid). Zooplankton: Parrotfish have no direct link to zooplankton in terms of predation. But if we consider the entire web, maybe a stretch. Wait, no. Let's re - examine. The food - web: Phytoplankton is eaten by unicornfish and zooplankton. Zooplankton is eaten by coral. Coral is eaten by parrotfish. Parrotfish and unicornfish are eaten by sharks.
• If parrotfish are overfished:
• Sharks (predators of parrotfish) have less food (so "Sharks would have fewer parrotfish to feed on" is correct).
• Parrotfish eat corals, so "Fewer corals would be consumed" is correct.
• Zooplankton: Coral eats zooplankton. If parrotfish are overfished, corals may have less predation (from parrotfish). If corals increase (because less are eaten by parrotfish), they would consume more zooplankton. But the option is "There would be too many zooplankton", which is incorrect. Wait, no, reverse. If parrotfish are overfished, corals (which eat zooplankton) may have a chance to increase (since less are eaten by parrotfish). So corals would consume more zooplankton, leading to fewer zooplankton. But this is a wrong path. Wait, no, the direct relationship: parrotfish have no predation on zooplankton. The correct relationships for the options:
• Unicornfish: Unicornfish's food source is phytoplankton. Parrotfish's reduction has no direct impact on unicornfish's food (phytoplankton) or its predator (shark, which also preys on unicornfish). So "Unicornfish would be greatly affected by a reduction of parrotfish" is incorrect.
• Phytoplankton: Unicornfish eat phytoplankton. Parrotfish have no direct impact on phytoplankton. So "There would be fewer phytoplankton" is incorrect.
• "Nothing would be affected..." is incorrect as we've already seen impacts on sharks and coral - consumption.

Answer:

Sharks would have fewer parrotfish to feed on, Fewer corals would be consumed.